Means for tightening the platform canvas of combined harvester thrashers



March 10, 1931. l. 1.. STEPHENSQN 1,796,127

MEANS FOR TIGHTENING THE PLATFORM CANVAS 0F COMBINED HARVESTER THRASHERS Filed May 29. 1930 swim doc Patented Mar. 10, 1931 PATENT OFFICE ISAAC L. STEPHENSON, or nannonzn'rm, TEXAS MEANS FOR TIGHTENING THE PLATFORM CANVAS OF COMBINED HARVESTER THRASHERS Application filedMay 29, 1930. Serial No. 457,285.

Theinvention relates to means for tighteningv the platform canvas of combined harvester-thrashers. v

The object of the present invention is to ,5 provide simple, practical and efficient means leaving his of strong, durable and comparatively inexpensive construction for tightening the platform canvas of combined harvester-thrashers and to provide a tightemngmeans of this character adapted to. enable the platform belt to be loosened at the end of a days work to prevent absorption of moisture by the platform canvas during the night from bursting, weakening or otherwise injuring the platform canvas and capable of enabling the platform canvas to be readily tightened by the operatoras required during-operations without position on a combined harvesterthrasher.

A further object of the invention is to provide'tightening means for a platform canvas adapted to enable the platform canvas of a combined harvester-thrasher to be conveniently tightened and loosened independent of the machines operation. I

WVith these andother objects in view, the,

invention consists in the construction and novel combination and arrangement of parts hereinafter described, illustrated in the accompanying drawings and set forth in the claims hereto appended, it being understood that various changes in the form, size, and minor details of constructio'n, within the scope of the claims, may be resorted to-without departing from the spirit of the invention or sacrificing any of the advantages thereof.

In the drawings Figure 1 is a side elevation of a portion of a platform provided with a canvas tightening means constructed in accordance with this invention.

Fig. 2 is a plan view of the same partly in section.

Fig. 3 is an end elevation of the platform and canvas tightening means.

- invention, 1 designates the mainframe of a platform provided'at its opposite sides at mg guides fora horizontal shaft 3 upon which 1s loosely mounted a roller 4 which receives the platform canvas 5 at one end of the platform and which may be constructed of wood, steel or any other suitable material. The roller 1 which turns freely on the shaft 3 does not constitute a drive for the platform canvas and the shaft 3 upon which the roller is mounted has keyed or otherwise fixed to it cog wheels 6 which mesh with rack bars 7 located above and arranged in parallelism with the guide slots2.

The rack bars 7 which are locked at opposite sides of the platform frame are preferably in the form of brackets and are provided at their ends with inner and outer attaching arms 8 and 9 as clearly illustrated in Fig. 1

of the drawing. The shaft is adapted to be rotate so that both ends of the shaft are moved simultaneously and uniformly inwardly or outwardly along the guide slots to tighten or loosen the platform canvas. Instead of proi'iding the slots shown in the drawing any other suitable guiding means 7 for the shaft 3 may, of course, be employed and the sa d shaft rotates only when it is moved inwardly and outwardly for tightening or loosening the platforn'i canvas.

1 The operating mechanism for moving the I shaft inwardly and outwardly to tighten or loosen the platform belt'comprises an oper ating lever 10 and a connecting rod 11 which is provided at its outer end with'a ring 12 forming a central circular opening to receive the shaft and permitting the latter to rotate in it. The ring 12 is retained on the shaft by a cotter pin13, but any other suitable means may, of course, be employed for securing the bearing end of the connecting rod 11 to the shaft and the bearing end may be of any other desired formation to provide a bearing opening for the shaft. Also a washer 14 may be interposed between the cotter pin and the 'ible centre bearing end of the connecting rod 11, as illustrated'in Fig. 3 of the drawing. I The operating lever 10 is fulcrumed intermediate of its ends at on a bracket 16' to provide a relatively short lower arm and a relatively "long'upper arm. llhe "glower arm is connctedby a suitable-pivot 17 "with the inner end of the connecting rod 11=andthe upper end of the long armiis designed torloe I I 7 V -ward'ly' withoutfistopping a machine, and

equipped with a rope ISor othe'r's'iiitable 'flextrol of the machine V I The bear ngor supporting bracket 16 I is provided with asubstantmlly semc rcular I topgportionhaving ratchetteeth -19--andform- "inga segmental ratchet member whichgis engaged by a spring actuated pawl 20*pivot allymountedontheupper'a-rm ofthe lever at 21 andfcontrolled a, latch' 'le ver 2-2. The latch lever '22 is connected by a rod 23 or otherjsuitable nieans with'the p'awl 2O andit passes through a guideQl: mounted-on theup- ;per arm ofthelever and-forming 'an'abut lnent ,for the upperend ofthe coiled spring 25' which is interposed between the guide24 and the pawl 20 foriu ging the'latter downwardly to maintain the same in engagement with the segmental ratchet member. "It will be clear that a pull on therope Will-move the shaftoutwardly"to stretch the platform can'- "vas and that as the canvas slacks during the operation of. the machine it may "be tightened and maintained taut-without the'opera- ;tor leaving his seat on-the' mac'hine andwitlr 7 out interfering with or stopping "tion of the machine; o

the operafiWha-t is claimed is j [1.- 111' atightener of the combination of a platform frame provided Withlong-itudinal guides open at their-outer ends, a shaft extending across/the platform frame from one side" to the other :inovable .7 ton adapt d amenabl tl il ver to; be manipulated by the operator from hieseat; on a combined harvester-thrasher Without leaving his position or relinquishing'his conclass describechthe platform frame and located above the gears and meshing with the same for causing uniform movement of the shaft along the said guides 'when pressure is applied to either end of the shaft to move the latter, a connecti'ng rodhaving a bearing portion arranged on the shaft-at one end thereof an operating 'lever eonnected with the other end of the said rod for .movingthe shaft inwardly and out- ;means for securing .itl -lever j ing its adj ust- :mre v v V p 3. In a tightener of the class described, the eomloination -,ofev platform frame provided with longitudinal guides open at their outer endsyfa I shaft extending across -r the platform "frame fl-(91110116 side :to the-other movable along the guides and havinga canvas re ceiving rol-ler loosely :mounted on it, gears f-fi-xed to the shaft, fixed rack bars amounted upon the platform framenan d located above :thegears and meshing -with the same for causing uniform 'movement of the shaft alongithe said guideswhen pressure is applied -toeither' end of the shaft to move the latter, afconnecting rod :having a hearing portion arranged on the shaft at one end thereof, an operating lever connected with the other end of the said rod for anoving ithe' shaft inwardly andfoutwardly 'Witl outstoppin'ga machine, a bracket support- .ing -the lever and provided with, a segmental ratchet member, a :pawl carried :byithe lever and engaging the ratchet for locking the lever-against movement in oneidirection; and r uneans connected with the'lever formovjing the \sameingthe opposite direct-ion, said pawl and -iratchet member being arranged to permit i 1 9KG3JlYG :t be (p ogr s vely tightened by the means for operating theilevert i v myhand. a a c ISAAO 'L SZEEPHENSON- along the guides and having a canvas;re ceiv'- ing roller loosely mounted on it, gears fixed to the shaft, fired rackbars-mounted upon the platforin frame[and located above the l ge'ar s and meshing with-gt he'saniefor -caus-.

. J 'in' g -uniform :ni'ovement of the sha'ft along the :said guides ovhen pressure -is"a.pp'l1ed to felther'end of the sha-ftto move'the {latter and means connected only with, one rend of the=shaft for'movingztheshaftinwardly and I ,o-utaward-lyfl and for [holding {the shaft in its adjustment withou'tnstopping a machine a II 2 lnatightenerhftheqelass described the vtcornbination f a platform frame provided 'jwith longitudinal Iguidesopen at their outer 1 ends; ,a a shaft pretending across the platform frame from one side :to the other movable along. th 'guidesand havinga canvas receiv- V ing'r'oller loosely mountedjongit gearsiixed to V the shaft; fixed rack bars mounted-upon the .ln testimony whereofl-liave hereunto set 

